Dehumidification units making utilization of the adsorptive action of an adsorbent have been known in the prior art. Referring to FIGS. 19 and 20, there is shown a structure of such a conventional dehumidification unit by way of example.
The conventional dehumidification unit Z0 is formed by sequentially laminating an adsorption element 31 having a large number of air ventilation passages 35, 35, . . . each supporting on its interior surface an adsorbent, and a cooling element 41 having a large number of air ventilation passages 45, 45, . . . in a 90-degree plane phase so that the air ventilation passages 35 are approximately orthogonal to the air ventilation passages 45.
And, in the dehumidification unit Z0, humid air (i.e., air to be processed) flows through the air ventilation passages 35, 35, . . . of each adsorption element 31, and, on the other hand, cooling air flows through the air ventilation passages 45, 45, . . . of each cooling element 41. On the side of the adsorption element 31, the moisture contained in the humid air is adsorption-removed by the adsorbent supported on the wall surface of the air ventilation passage 35, and the humid air is changed into a stream of low-humidity air. Meanwhile, heat of adsorption, generated by such moisture adsorption on the side of the adsorption element 31, is absorbed by heat exchange with the cooling air flowing through the air ventilation passage 45 of the cooling element 41. As the result of this, the adsorption capability of the adsorbent will be maintained at satisfactory levels over a long period of time.
And now, as shown in FIGS. 19 and 20, the conventional dehumidification unit Z0 is made up of the adsorption elements 31 and the cooling elements 41, and each adsorption element 31 is composed of an air ventilation passage forming member 32 bent in the shape of a corrugated plate, and a pair of tabular side-plate members 33, 33 respectively firmly attached to both sides of the air ventilation passage forming member 32. Both the air ventilation passage forming member 32 and the side-plate members 33, 33 are formed of fiber paper made of ceramic fibers, and an adsorbent, such as silica gel etcetera, is supported on their surface.
On the other hand, each cooling element 41 is made up of an air ventilation passage forming member 42 bent in the shape of a corrugated plate, and a pair of tabular side-plate members 43, 43 respectively firmly attached to both sides of the air ventilation passage forming member 42. Both the air ventilation passage forming member 42 and the side-plate members 43, 43 are formed by a sheet metal (thin metallic plate) made of aluminum etcetera.
Problems to be Solved
Meanwhile, in the dehumidification unit Z0 formed by sequential laminations of the adsorption element 31 and the cooling element 41, the air ventilation passage 35 on the side of the adsorption element 31 and the air ventilation passage 45 on the side of the cooling element 41 are adjacently formed, with a two-ply wall part (formed by attachment of one of the side-plate members 33, 33 of the adsorption element 31 to one of the side-plate members 43, 43 of the cooling element 41) lying between the air ventilation passage 35 and the air ventilation passage 45 (see FIG. 20). Accordingly, heat exchange between the humid air on the side of the air ventilation passage 35 of the adsorption element 31 and the cooling air on the side of the air ventilation passage 45 of the cooling element 41, i.e., heat transfer from the adsorption element 31 towards the cooling element 41, is always conducted through the aforesaid two-ply wall part made up of the side-plate members 33, 43.
As the result of this, heat-transfer resistance is high during the time of heat transfer between the adsorption element 31 and the cooling element 41, because of which the capability of removal of heat of adsorption by the use of cooling air declines. This results in inviting a drop in the dehumidification capability of the dehumidification unit. Therefore, there is still room for improvement in maintaining the dehumidification capability of the dehumidification unit.
In view of the above, the present invention was made. Accordingly, an object of the present invention is to provide a dehumidification unit capable of maintaining its dehumidification capability at high levels over a long period of time by accomplishing improvement in the performance of heat transfer between the adsorption element and the cooling element, and to provide an adsorption element suitable for use in such a dehumidification unit.